Hrrrm, I never had a problem with the MP valve covers, big or small block. When I install the covers I lay a thin line of RTV on the valve cover, then put the gasket on, put another line of RTV, install the cover on the head, torque it down hand-tight, and let it sit till dry. The only problem with this method is that the cover is a pain in the ass to remove as it pretty much bonds itself together, however like I said before....I dont get any oil leaks.